The systematic review covered 83 scientific papers. The most compelling evidence was found for the use of ketamine for the treatment of depression and bipolar depression. Symptoms improved within one to four hours after a single dose of ketamine and lasted for up to two weeks. Some evidence suggests that retreatment may prolong the effect, but better research is needed to determine how long.
In addition, the introduction of ketamine reduced the number of suicidal thoughts. This improvement was observed as early as four hours after administration and lasted from three days to a week on average.
Ketamine is used as an anesthetic agent in medicine and veterinary medicine. Less commonly used as a pain reliever and to treat bronchospasm.